There has never been a way to see the past clearly here on Earth. Archaeologists can discover fossils and artifacts, geologists can analyze rock, and anyone can open a history book or look at an old painting. But none of these things show exactly what anything looked like at the time.
Not so when it comes to the work of Caitlin M. Casey, an associate professor in UT’s Department of Astronomy who examines the past every day as an observational astronomer.
Casey is one of the leaders of a team of scientists from around the world who will use the recently launched James Webb Space Telescope – the most powerful space telescope ever built – to uncover the secrets of how our universe began billions of years ago. ‘years.
“When the first galaxies and stars first lit up, there was a lot of mystery in the very early stages of the universe,” Casey explains. “We’re basically trying to write the history books, going all the way back to the Big Bang.”
The findings of the James Webb Space Telescope – which Casey calls “the ultimate tool that astronomers have been waiting for decades” – are expected to be groundbreaking. From its vantage point orbiting more than a million miles from Earth, the telescope will be able to capture deeper, richer, and more informative images of space than images from any telescope before it, including including the Hubble.
Casey would know. She works with all kinds of telescopes around the world to decipher their images, gleaning information from what others look like as a mosaic of dots, swirls and pops of light.
Now his team has secured nine full days with the James Webb Space Telescope (JWST) for their project, COSMOS-Webb. It’s similar to the Hubble Deep Field project which captured images of the sky for 10 consecutive days in 1995, but COSMOS-Webb is even bigger and more ambitious.
“The Hubble Deep Field covered about a patch of sky so small it could be behind the head of a pin if you held that pin at arm’s length,” Casey says. “We cover an area equivalent to three full moons. It’s a big chunk of sky. We expect to find something like a million galaxies in the COSMOS-Webb image.
With the nine days of images, Casey and his team will analyze patches of light in the background, not the large, beautiful galaxies that will be clearly visible in the JWST images. To us, these specks might be more like dust on a screen, but to Casey, they’re literally images of the past taken in real time, the galaxies that may or may not exist still visible due to their light that has taken so long to travel to us. It also represents a looping moment for her – Casey was inspired to become an astronomer after seeing the Hubble Deep Field images as a child.
“I remember seeing these images and being totally amazed by their depth and distance, showing us objects farther away than anything humans have ever seen,” Casey says. “I was just addicted. I got as many books as I could and tried to learn as much as I could.
Casey and his team’s time with the telescope won’t be until December 2022 or April 2023, when the telescope will be able to get the images they need. But this is only the first round of research involving JWST. The telescope is expected to operate for at least 10 years, which means we’re not far from learning the answers to some of the biggest questions on Earth: How did we get here? Are we alone?
“Even though [the telescope] was to last [only] 10 years we will be blown away by the data we get,” says Casey. “JWST is just going to revolutionize astronomy in so many ways. And I think the whole community, and I hope the whole world, is as excited as I am.
Credits: NASA/Chris Gunn; NASA/Bill Ingalls